你说的是不是鳞式?
鱼的鳞式=侧线鳞数(侧线上鳞/侧线下鳞)
具体怎么数看这张图http://sz.photo.store.qq.com/http_imgload.cgi?/rurl2=e508e25a66605717ca26bdda818be8a250efd272e05ec6592639a3620218fd2c4dc6225ba4934b3c0237a100c4491cbd9d4873e8128ce077744f62887b8d17d01a93ee3bc999910558e8622633414c7aeffd9889